WASHINGTON (Bloomberg) -- Six days after General Motors Co. recalled almost 800,000 Chevrolet Cobalts and Pontiac G5s for a defect that could cause surprise engine shutdowns, lawyer Lance Cooper, a solo practitioner in Georgia, sent government regulators a letter: There are more faulty GM models out there.

Six days later, on Feb. 25, the automaker more than doubled its recall to include other mid-2000s GM models, including Saturn Ions and Pontiac Solstices, saying their ignition switches could unexpectedly turn off if jostled by a driver or weighed down by a heavy ring of keys, cutting power to the engine and air bags.

The recalls have clouded the reputation of the biggest U.S. automaker, spurred new searches for deaths connected with the cars and raised a question that investigators in Washington, New York and inside GM are pursuing in parallel: Why didn’t GM recognize the potential dangers sooner?

To date, Cooper may have dug the deepest.

“He single-handedly set the stage for this recall,” said Sean Kane, an auto-safety analyst who credits Cooper for being the first to create a public record of what GM did with the ignition switch. Kane, the president of Rehoboth, Mass.-based Safety Research & Strategies Inc., has worked with plaintiffs’ lawyers on suits involving sport-utility vehicle rollovers, tire recalls and unintended acceleration in some Toyota Motor Corp. models. He consulted on Cooper’s suit against GM.

“But for the things he has done, this thing doesn’t happen,” Kane said.

Dozen engineers

Bringing a wrongful death lawsuit against GM, Cooper obtained more than 32,000 pages of related lawsuits and other documents from the company, deposed about a dozen of its engineers and gathered assessments of the ignition issue from dealers. According to some of the depositions, reviewed by Bloomberg News, the defect was known to some dealers, engineers and managers since at least 2004.

GM settled with Cooper’s clients for an undisclosed amount last September. Five months later, the company announced its recall. Shortly after that, it gave government regulators a timeline of the company’s knowledge of the defect that was consistent with Cooper’s findings, including engineers’ decade-long awareness of it.

GM spokesman Greg Martin declined to comment on Cooper’s lawsuit. The company has apologized for its delay in recalling the models, said its decision-making process “was not as robust as it should have been” and said it is studying ways to improve how it addresses defects.

Tab Turner

Cooper is no big-firm litigator. The 51-year-old graduate of Emory University School of Law employs a handful of people in Marietta, just outside Atlanta. He litigated his case against GM mostly with the help of his paralegal, Doreen Lundrigan. His experience with GM echoes that of Tab Turner, the Arkansas-based sole practitioner whose personal injury suits helped lead to the 2000 recall of 6.5 million Firestone-brand tires from Japan’s Bridgestone Corp., many of them on Ford Motor Co.’s Explorer SUV.

Cooper characterizes himself as a “free-market guy” who believes the courts are necessary to police those markets. “This is the poster-child case for why the civil-justice system is necessary: NHTSA knew about this for a number of years, and they didn’t get to the bottom of it,” Cooper said in an interview.

The National Highway Traffic Safety Administration has said it didn’t force GM to conduct the recall sooner because GM hadn’t provided timely information about the connection between defective ignition switches and failing air bags. Nathan Naylor, a NHTSA spokesman, declined to comment further.

Bronco IIs

Cooper said he took on his first product liability case in the early 1990s, involving a Ford Bronco II rollover. “It sort of led to more cases, and as a result, this is where I am,” he said.

Since 2009, according to people in his firm, Cooper has reached confidential settlements with GM in three other lawsuits involving alleged vehicle defects. Cooper has secured more than 50 settlement and trial awards, they said, including nine for amounts greater than $5 million.

Cooper was approached in February 2011 by the family of Brooke Melton, a 29-year-old Georgia pediatric nurse who died in March 2010 after her 2005 Chevy Cobalt lost power, veered into the opposite highway lane and hit an oncoming car. The Melton family couldn’t be reached for comment.

Melton’s family received a recall notice from GM soon after the crash, Cooper said, related to an issue with the Cobalt’s power-steering.

Black box

In June 2011, Cooper filed a wrongful death suit against GM on behalf of the family in the State Court of Cobb County, Ga. That fall, Cooper asked GM for information related to the power-steering issue.

He soon changed his focus. Information from the black box in Melton’s Cobalt indicated that power had been cut not only to the power steering, but also to the rest of Melton’s car, Lundrigan said. Meanwhile, Cooper also became aware of bulletins GM sent to dealers in 2005 and 2006 pointing out scenarios in which drivers could inadvertently turn off the ignition in various GM models.

In a revised complaint filed in March 2013, Cooper alleged that as Melton drove her Cobalt on Georgia’s Highway 9, her key moved out of the run position, shutting off the engine and causing her to lose control and strike an oncoming car.

“The impact caused Brooke’s vehicle to travel off the highway and into a creek,” leading to injuries that resulted in her death, according to the complaint. GM was accused in the complaint of negligence in designing, testing and manufacturing such a car and of failing to adequately warn consumers.

'Internal workings'

In total, the firm deposed some 30 people familiar with the ignition-switch issue, including about 12 GM engineers, Lundrigan said.

Cooper’s “focus on getting really into the internal workings of that corporation, getting into their engineering drawings, communications” helped pressure GM, said Dennis Cathey, a Georgia lawyer who has known Cooper for more than a decade and worked with him on automotive defect cases. “He has an innate sense of knowing that something could be wrong, and seeks to find out his proof to establish that wrong.”

Even so, Cooper hadn’t received all that he sought from GM. In September 2012, he had asked GM for information on the ignition switches -- including related lawsuits and documents on a replacement part described in the dealer bulletins.

'Unspecified objections'

The following January, GM provided “a lot more documents,” Cooper said. They provided even more, he said, after the judge issued an order in February 2013 overruling “GM’s general and unspecified objections” to several of Cooper’s discovery requests and requiring the carmaker to produce “all responsive documents and materials” by the end of the month.

In subsequent depositions, though, GM engineers referred to documents that the automaker hadn’t provided, Cooper said. In June, he filed a motion seeking penalties against the carmaker for withholding information.

In September, two months ahead of the suit’s trial date, GM and the Meltons reached a confidential settlement, Cooper said. GM hadn’t provided the additional documents, he added.

A related suit could still reach trial.

Cooper also sued Thornton Chevrolet, the dealership in Lithia Springs, Ga., where Melton brought her car for repair just days before her fatal accident, according to the lawsuit. On the visit, the suit alleges, Melton raised concerns about the engine shutting off during driving. Thornton failed to identify and implement the GM bulletin to dealers aimed at addressing the problem, Cooper said. While the judge in the case has ruled on pretrial issues, a trial date hasn’t been set, according to Lundrigan.

GM’s recall, and word of Cooper’s knowledge in the case, has given the solo lawyer a sudden popularity. The firm has received more than 70 calls in the past few weeks -- from would-be plaintiffs, attorneys seeking to partner with Cooper and people thanking him for publicizing the issue -- said Victoria Schneider, the firm’s marketing director.

“I’ve talked to a few lawyers,” Cooper said.

Protective order

Cooper is bound by a protective order in the Melton case, in effect since December 2011, that bars him from sharing material and deposition testimony GM has designated confidential. He must also return GM’s documents after the case is finished. Copies of depositions in the case reviewed by Bloomberg News are heavily redacted, with the majority of some testimony blacked out.

While Cooper hasn’t filed more lawsuits since GM’s recall announcements in February, his firm’s investigation of the situation is continuing, he said.

“If we were to file another lawsuit against GM, we’d call GM’s lawyers up and we’d say, ‘Hey, we’ve got all these documents, let us use them in the new case.’ If they say no, we’d file a motion with the judge,” he said. “We’ve had these situations before where most of the time, the manufacturer will be reasonable and allow you to use them.”

Cooper said the process has been gratifying for Melton’s family. “They hope the public will now know the whole truth about what GM did,” he said.